The 24-pounder long gun was a heavy calibre piece of artillery mounted on French warships of the Age of sail, second only to the 36-pounder long gun. They were comparable to the Canon de 24 Gribeauval used by the Army as its largest piece of siege artillery. 24-pounders were used as main guns on the heaviest frigates of the early 19th century and on fourth-rate ships of the line, on the second deck of first-rate ships of the line, and on the second deck of a few large third-rates.